Range from the cheapest cat flap installation £68 (Constantina Locksmith based in N15) to the dearest cat flap installation £320 (Bspec Ltd based in E5).
Comparing carpenter & joiners estimates for installing a cat flap gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes to fit a cat flap in E9 by posting a job with HaMuch and we will send it to carpenter & joiners in E9.